Operational rules and “hacking” detection is implemented across online professional competitive gaming contexts in effort to thwart manipulation and encourage fair play. Violation of “unwritten” rules and implicit local norms, however, are harder to track. Using boundary-work theory, this article demonstrates how different perspectives of unsportsmanlike behavior are defended and disputed by spectators within the esports mode of Counter Strike: Global Offensive (CS:GO). Triangulating data drawn from 50 hr of online observation followed by spectator interviews, this article examines how boundaries of (un)acceptability are drawn and/or redrawn around specific and ostensibly unsportsmanlike behaviors associated with “bad mannering,” “throwing,” and “bug exploiting” in CS:GO. These broad spectra of behavior imply a degree of complexity in local esport gaming contexts, engendering a protean boundary that sets it apart from more traditional views of sportsmanship and would benefit from further critical scholarship.